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Data from experimental and human cryptosporidiosis have established a major role of specific immunity in the control of Cryptosporidium parvum infection. In this work, alterations in spleen and Peyer's patch (Pp) lymphocytes were investigated in the course of a spontaneously resolutive gut cryptosporidiosis in four-day-old suckling NMRI mice infected with either 4 x 10(5) or 30 viable oocysts. Oocysts from entire small intestines, and spleen and Pp lymphocytes were examined using flow cytometry from day 7 to day 27 post-infection. Compared to uninfected animals, a 3-5 fold increase in the numbers of spleen TCR alphabeta+, CD4+, CD8+, TCR gammadelta+ and CD45R/B220+ lymphocytes was observed on day 17 post-infection in heavily infected animals. In Pp, more than ten-fold increases were observed, except for TCR gammadelta+ lymphocytes. At termination of infection, i.e. on days 21-23 after ingestion of 4 x 105 oocysts, T and B lymphocytes decreased rapidly in both organs, and remained lower than in uninfected animals on days 19-23 post-infection. In mice infected with 30 oocysts, similar alterations were observed in Pp, but not in spleen. Data suggest that in normally developing mice, clearance of gut C. parvum infection is associated with an initial increase in systemic and local lymphocyte numbers, followed by their decrease to below control levels during the recovery phase.

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Anticardiolipin antibodies (aCL) were investigated in 137 individuals chronically exposed to malaria and living in Africa and Asia. They belonged to several groups according to parasite (Plasmodium falciparum or vivax) and clinical manifestations (i.e. asymptomatic parasite carriers, acute uncomplicated attack or severe malaria episodes). aCL were measured in an enzyme immunoassay (ELISA) performed in the presence of either goat serum (aCLs) or gelatin (aCLg). In a group of 53 patients with autoimmune manifestations (i.e. antiphospholipid syndrome and/or lupus), detection of IgG but not IgM aCL was markedly reduced in the presence of gelatin. In malaria donors, high prevalence of serum co-factor-independent IgG and IgM were detected, and the presence of goat serum in the assay consistently decreased their detection. aCLg levels were found to be related to the clinical/endemic status of donors. IgG aCLg were found to be higher in asymptomatic P. falciparum carriers than in patients with uncomplicated acute or cerebral malaria. IgM aCLg were higher in the cerebral malaria group than in groups with uncomplicated acute malaria patients or asymptomatic individuals. Data suggest that using a serum co-factor independent, sensitive ELISA, aCL are commonly detected during malarial infections and related to malarial infection status.

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Defective apoptosis is a mechanism which could possibly explain B chronic lymphocytic leukemia (B-CLL) cell accumulation. Differences in evolution and prognosis of B-CLL patients may be due to heterogeneity in apoptotic cell death. We studied the apoptotic response to in vitro gamma radiation of blood mononuclear cells from 18 untreated B-CLL patients. In cells irradiated with 2, 4 or 8 Gy and then cultured for 20 hours, the percentage of trypan blue excluding (viable) cells was not modified (>92%). An apoptotic response to irradiation was detected in the majority of the patients, but the individual percentage of apoptotic cells varied widely (8 to 81% after 8 Gy irradiation) in individual cases. The flow cytometric analysis of nick-end DNA labeling demonstrated a dose effect of irradiation, particularly in patients with an apoptotic response of over 20%. In the future, a valuable clue to the selection of irradiation regimens for B-CLL patients may be the investigation of correlations between in vitro radiation-induced apoptosis and the in vivo response to radiation therapy.

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IgE multiple myeloma is a rare disease characterized by a high frequency of Bence-Jones proteinuria and plasma cell leukaemia when compared to other isotypes of monoclonal proteins. Only 35 cases have been reported. We describe a 70-year-old woman with a stage III IgE kappa multiple myeloma presenting with a sacral plasmacytoma. Immunological and biochemical studies showed IgE kappa producing tumoral plasma cells. Serum total IgE was high without clinical symptoms suggesting an hyperIgE syndrome or mast cell activation. The patient underwent surgical removal of the sacral tumor and monthly melphalan-prednisone treatment together with intravenous pamidronate infusions. Magnetic Resonance Imaging (MRI) of the dorsolumbar spine revealed an epidural process leading to T6-T9 radiotherapy. Bone densitometry showed a decreased bone mineral content supporting the management of myeloma-related osteoporosis with bisphosphonate infusions. A good partial response with plateau-phase and increase of bone mineral content was achieved after 1 year of treatment and still persists after a 28 months follow-up.

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The performances of nine commercial kits and an in-house method (HM) for the quantitation of anticardiolipin antibodies (ACA) have been evaluated in a multicenter study. Ninety control and patient samples and six standards from Louisville University were run with kits and with the HM. Marked differences in positivity rate between kits were observed, ranging from 31 to 60% for IgG and 6 to 50% for IgM. Concordance between kits occurred in 59 and 51% of samples for IgG and IgM respectively. Concordance coefficients (kappa) ranged from 0.13 to 0.92. Slopes of regression lines between the declared units of Louisville standards and the units measured from the calibrators of the kits showed great diversity and ranged from 0.159 to 0.931 for IgG and from 0.236 to 0.836 for IgM. The beta 2-glycoprotein I (beta 2-GPI) content of the dilution buffers and the wells supplied with the kits revealed noticeable differences. However samples containing anti-beta 2-GPI antibodies were classified similarly by all but one kit. In contrast the ability to measure samples devoid of anti-beta 2-GPI antibodies differed markedly between the kits. This study shows that differences in positivity rates between the commercial kits may contribute to the differences in ACA prevalence rate found in the literature. The choice of cut-off levels may partly explain the moderate concordance between the kits. In addition some samples behave very differently depending on the kits. In spite of the expression of results in PL units, standardization of ACA assays has not been achieved.

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The significance of blood TcR gamma delta+ lymphocyte level was evaluated in the context of immunodeficiency and infections in 209 HIV-1-infected patients. Blood TcR gamma delta+ lymphocyte values were found higher in patients belonging to the CDC group II/III than those in the CDC groups IV C1 and IV D (P < 0.001) and P < 0.01, respectively). TcR gamma delta+ lymphocyte counts were lower in patients with oral candidiasis (P < 0.01), and in association with pneumocystosis or toxoplasmosis (P < 0.001). In 81 patients with a detectable HIV-1 p24 antigenemia, TcR gamma delta+ lymphocyte counts were lower than those in nonantigenemic patients (P < 0.001). In the CDC II/III group, p24-antigenemic patients exhibited lower TcR gamma delta+ cell counts than those in patients without antigenemia (P = 0.06). Data suggest that depletion of the TcR gamma delta+ lymphocyte subset characterizes HIV-1-infected patients with oral candidiasis, pneumocystosis, toxoplasmosis, and/or HIV-1-antigenemia.

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Human antibody response to Cryptosporidium parvum has been previously shown as involving immunoglobulin (Ig)M and IgG isotypes. The interest in anti-cryptosporidial IgA antibody response has been recently stimulated by studies on the therapeutic effects of secretory IgA antibodies to Cryptosporidium in animal models and in patients. In the present study, isotypes of serum anti-Cryptosporidium antibodies have been characterized in donors of the following categories: (a) healthy adults, (b) healthy children, (c) immunocompetent children with transient cryptosporidial diarrhea, (d) HIV-infected patients without clinical and parasitological evidence of Cryptosporidium infection and (e) AIDS patients with cryptosporidial diarrhea. Antibodies were detected using C. parvum oocysts purified by density gradient centrifugation from bovine faeces. The IgA antibodies were revealed using alpha-chain specific antibodies. Indirect immunofluorescence analysis with oocysts was used as control. Although high levels of serum antibodies of the IgA class were detected in some donors in the group of healthy adults, elevated values were consistently found in HIV-infected patients. Higher values were found in HIV patients with clinical cryptosporidiosis. The presence of a secretory component in serum IgA antibodies in these patients has been documented. Data indicate that IgA serum antibodies are produced as well as IgM and IgG antibodies upon contact with the parasite, and suggest that elevated IgA serum antibodies to Cryptosporidium are not associated with protection in HIV patients.

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